Casting machine



CASTING MACHINE Filed Aug. 3. 1938 D. H. GARTH CASTING MACHINE April 15,1941.

Filed Aug. 5, 1938 E5 mwwW-Smm 2 D. H. GARTH CASTING MACHINE Filed Aug.3, 1938 m Shwwts-Shewt 3 Jhwni or W W 41mm Patented Apr. 15, 1941 UNITEDSTATES PATENT OFFICE astfil itllm Donald H. Garth, Chicago, Ill.Application Am #1938, Serial N0. 222,737

(Cl. 2H7) 8Claims.

This invention relates to a casting machine.

The particular embodiment which I shall herein illustrate and describeis a machine for die casting metal objects.

One of the main objects of the invention is to provide a casting machinewhich is operable expeditiously to provide a plurality of good castingsof the same shape or in diflerent shapes at the same time, and a machinein which an variation in the shapes of any number or all the pluralityof castings produced at the same time may be readily accomplished.

It is a further Object to reduce or substantially eliminate heat lossfrom the molten metal in its delivery from the molten metal containerthrough the gate and runner means to the mold means, so as to preventchilling or solidification of the molten metal in the gate or runnermeans or elsewhere in its passage to the mold means, and to assure thatthe molten metal is delivered into the mold means in the desired moltencondition completely to 1111 the mold means and produce good homogeneouscastings at all times.

The maintenance of the metal in molten condition in its passage throughthe gate and runner means eliminates cleaning of gates and runners fromthe finished work and clogging of the metal in its passage to the moldmeans. The master mold plates are preferably arranged so that the moltenmetal will drain from the runners and gates when the mold plates areparted, and the base section of the machine is preferably formed to holda removable tray or crucible for catching the overflow or waste metal inoperation.

It is a further object of the invention to provide an improveddisplacement method of delivering the molten metal from the molten metalcontainer to the mold means. In the illustrated embodiment, thisdisplacement method; in conjunction with the arrangement oi the moldplates, results in utilization of the force oi gravity to fill the moldswithout the use of forced air or the like, and permits accuratelycontrolling the amount of metal delivered to the mold plates inaccordance with that required properly to fill the molds. The lead fordelivering the molten metal from the container therefor to the gatemeans of the mold plates is preferably enclosed to reduce oxidation 01'the metal.

It is also an object to provide an improved master mold plate for notonly holding the replaceable molds or mold holders, but also adapted forartificially cooling the molds without loss of heat from the moltenmetal in its passage through the gate and runner means of the moldplate. It

desired, the mold plate may be utilized to apply heat to the molds tomaintain the metal in the molds in molten condition until the desiredfiliin of the molds is accomplished.

Another object is to provide means for adjusting the casting molds inthe master mold plates for the purposes to be hereinafter described, andfor locking the molds in adjusted position; also adjusting means forsecuring perfect fitting of the matched mold plates and the moldscarried thereby, and guide means for guiding the plates into perfect fitand for preventing relative sagging oi the plates. 7

Another object is to provide a casting machine of simple and inexpensiveconstruction that may be operated conveniently, and an improved carriagearrangement and movement imparting means for the relatively movablemaster mold plate.

Further objects and advantages of the invention will appear from thefollowing detailed description, taken in connection with theaccompanying drawings, inwhich:

Flgure l is a side elevational view, partially in section, of a castingmachine embodying the present invention;

Figure 2 is a vertical section taken on the line 2-2 of Figure 1;

Figure .3 is an end view of the casting machine looking from the lefthand end, as viewed in Figure 1;

Figure 4 is a horizontal section taken on the line 4-4 of Figure 2;

Figure 5 is a fragmentary on the line 5-5 of Figure 4;

Figure 6 is a back side view of one of the master mold plates,showingthe means for delivering a cooling medium thereto and.discharging same therefrom;

detail section taken Figure 7 is a fragmentary detail section taken onthe line 1-1 of Figure 3;

Figure 8 is an elevational view of the mold insert shown in Figure 5;and

Figure 9 is an elevational view showing a pair of cooperatingcomplementary mold inserts for I producing another form of casting.

The main frame of the particular machine illustrated in the drawingscomprises a base section Ill supported upon suitable legs or standards-II. The base section I 0 and standards ll may be formed of cast iron orother suitable material. The two master mold plates for holding themolds are indicated at [2 and I3. One of these plates, 1. e., the mastermold plate i3, is relatively stationary. This relatively stationaryplate I: is formed integral with an upright supporting member l4, and issupported in upright position thereby as shown. The supporting member orstandard I4 is of angular and webbed or other suitable structural format the bottom, and is bolted at l5 to the base section Ill. The basesection III is hollowed out at I6 to receive a removable tray orcrucible I'I formed of graphite or other suitable material. Thiscrucible is adapted to catch the overflow and waste metal in theoperation of the machine.

A carriage I8 is mounted for sliding movement upon the top of the basesection 10. Tongue and groove engagement is provided at I! between thiscarriage l8 and the base section l0 (Figure 3) for guiding the carriageit toward and away from the mold plate I3. The cooperating portions ofthe base section and carriage l8 are fully machined, and the carriagemay be formed of cast iron or other suitable material. The carriage I!has an aperture adapted to register with longitudinally spaced apertures2| in the base section III, and a pin 22 is provided for insertionthrough the aperture 20 and into any of the apertures 2| with which theaperture 20 is registered to lock the movable carriage l8 in any desiredposition along the base section Ill.

A second carriage 25 is mounted for sliding movement upon the top of thecarriage l8. Dovetail engagement is provided at 26 between this secondcarriage 25 and the carriage l8 (Figure 3) for guiding the uppercarriage 25 upon the lower carriage l8 longitudinally toward and awayfrom the mold plate IS. The cooperating portions of the carriages l8 and25 are fully machined, and the upper carriage 25 may be formed of castiron or other suitable material.

A handle 21 is provided for manually moving the upper carriage 25longitudinally along the lower carriage I! on the ways provided by thedovetail engagement at 26. The handle 21 is fixed upon the outer end ofa cross shaft 28 which is turned by turning the handle. The shaft 28 isjoumaled in the carriage I8, and has a gear 29 fixed thereon to turnwith the shaft 2!. The gear 25 meshes with a flat bed gear or toothedrack 30 mounted on the under side of the top carriage 25, so that whenthe handle 21 is turned the action of the gear 29 on the rack or gear 30will cause the upper carriage 25 to move toward or away from the moldplate l3.

Instead of manually turning the cross shaft 28, I contemplate theprovision of power means for this purpose. I also contemplateautomatically controlling the power means for moving the upper carriage25 automatically to close and open the mold means. Where the machine isoperated automatically, the automatic operation will preferably be timedto permit unloading or removal of the castings while the movable mastermold plate is parted from the stationary master mold plate. I alsocontemplate automatically controlling the displacement delivery of themolten metal to the mold means so that this delivery of molten metalwill be timed to take place when the mold is closed.

The upright and relatively movable master mold plate I2 is bolted at 32to a generally elbow shaped arm 33, which arm 33 in turn is bolted at 34to the top of the upper carriage 25. The movement of the lower carriagel8 provides for bringing the mold plate l2 into and out of the desiredrelation with respect to the matching mold plate I: and for providingrelatively great travel to free the mold plates from relatively longobjects. The movement of the upper carriage 25 provides for bringing themovable mold plate l2 into and out of engagement with the relativelystationary mold plate [3.

Adjusting bolts 36, threaded through flanges on the upper carriage 25and into engagement with the mold plate l2, are adapted for adjustingthis plate l2 into parallel relation and accurate registration with themold plate l3 so that these mold plates and the casting molds carriedthereby and the cooperating gates will match or fit perfectly when inclosed relation when the plate I2 is in closed position. Further toinsure perfect fitting of the matched mold plates, the plate l3 hasguide pins 31 secured at 31' thereto, and these pins 31 have slidingengagement in apertured lugs 38 projecting laterally from the oppositesides of the mold plate I2 to guide the plate l2 into perfectly fittingengagement with the plate 13 and to prevent relative sagging between themold plates.

The matched master mold plates I2 and iii are formed of metal or othersuitable material that is preferably a relatively good conductor ofheat. Each plate is hollow and shaped generally to a four-sided hollowbox-like form. The

cavity 40 (Figure 4) within each plate [2 and I3 is provided primarilyfor holding and circulating water or other suitable cooling mediumwithin the plate and around the bodies of the molds or mold holderswhich are in direct contact with the cooling medium, as will presentlyappear. This cooling hastens congealing or solidification of the hotmetal. It is to be understood, however, that the metal will congeal orsolidify with natural cooling and that, therefore, the coolingarrangement shown may be omitted within the scope of the broader aspectsof the present invention. Moreover, if desired, the cavity 40 of themold plates may hold a heating medium for applying heat to the molds tomaintain the metal in the molds in molten condition until the desiredfilling of the molds is accomplished.

In the illustrated embodiment of the invention, the mold plates l2 and13 are provided with a plurality of matched mold holders 42. Six ofthese mold holders 42 are shown in each of the mold plates l2 and I3,but the particular number of such mold holders in each mold plate mayvary .widely within the scope of the present invention. I contemplateone or more molds within the broader aspects of the invention.

Each mold holder 42 is of generally tubular form, provided at its moldcarrying end with an integral annular flange or collar 43, and threadedexternally at 44. The opposite end of each mold holder 42 is reduced andexternally threaded at 45. The mold plates l2 and I3 have registeringopenings 46 and 41 through which the mold holders are inserted from thefront sides of the respective mold plates and into the positions shownin Figure 4. The threads 44 on the mold holders have threaded engagementwith the front side of the mold plate at the openings 46, but, thereduced and threaded ends 45 pass freely through the openings 4'I,in theback wall of the mold plate. The mold holders are thus inserted into themold plates from the front sides of the respective plates, and continuethrough the cavities 40 and through the .back sides of the mold plates.

The outer surface of the front wall of the mold plate I3 is providedwith a recess concentric with each pair of aligned openings 46 aasaoccand 41 for receiving the flanges or collars 43 on the mold holders 4:,and also receiving adjusting nuts 5| threaded upon the threaded portions44 of the mold holders. Suitable washers 52, beneath the nuts 5|, seatupon the inner ends of the recesses SI and seal the openlugs 46.

The outer surface of the front wall of the mold plate It is faced with alayer 54 of very good heat insulating material such as asbestos millboard, dolomite refractory, or other suitable material which is a Verypoor conductor of heat. A suitable material for this Purpose is formedof asbestos and magnesia, the asbestos providing the desired heatinsulating characteristic and the magnesia making the material resistantto high temperatures so that the facing will not break down or decomposeunder such temperatures. The facing 54 may be formed of any materialhaving the desired heat insulating properties to accomplish the resultswhich will presently appear. This facing may be secured to the outersurface of the mold plate I3 by screws (not shown), or in any othersuitable or preferred manner.

In the illustrated embodiment of the invention, the mold members 60. arein the form of inserts preferably formed of metal or other good heatconducting material. The outer ends of the particular mold inserts shownare enlarged to seat upon the outer ends of the mold holders 4%. Theseenlarged outer ends of the mold inserts fit in openings 6| in the heatinsulating facing 51. The inner reduced ends 62 of the mold inserts 60fit telescopically within the mold holders 42, and the mold inserts arereadily removable so that they may be replaced or interchanged asdesired.

As shown in Figure 5, pins 64, secured to the mold plate I3, projectinto the recesses III, and are adapted to engage in openings in the nuts5! to hold these nuts 5| against turning when the mold holder n isinserted into place. Thus, by grasping the opposite end of the moldholder 42 or engaging a suitable tool therewith, the

mold holder may be turned, and this turning movement threads the moldholder axially through the nut 5| to dispose the outer flanged end 43 inposition to seat the mold insert 60 with its outer end flush withthe'outer surface of the same securely in place. The various moldholders may be adjusted selectively as desired merely by loosening thelock nuts 65 and turning the mold holders to adjust same axially to thedesired position, whereupon they may be secured in adjusted position bytightening the nuts 65. Washers 61 are preferably interposed between thelock nuts 55 and the back surface of the mold plate I3 to seal theopenings 41.

The two master mold plates l2 and I3 and the various mold holders l2 andmold inserts 60 in each of the master mold plates I2 and I3 areidentical, except for the casting cavities 68 which may be alike ordifferent, as desired, so that the foregoing description will sufllcefor all. In the illustrated embodiment, the mold holders are insertedbefore the insulating facing 54 is applied, but this may vary within thescope of the present invention.

Each mold insert has a casting cavity 68 for casting the metal object tothe desired shape.

The present machine will handle all kinds of metals or alloys, such asaluminum, bronze, white brass, or any other metals or alloys, and isadapted for producing dense and homogeneous objects of any shape orsize. The molds shown in Figures. 4 and 8 have the mold cavities 6|shaped to produce water pump impellers for a well known make ofautomobile. To provide an opening for receiving the shaft for theimpeller the molds 60 shown in Figures 4 and 8 are bored at 69 tosupport cores III of suitable core material in the casting operation.This may, of course, vary widely within the scope of the presentinvention. For example, the shaft may be placed directly in the castingmachine, with a knurled or otherwise roughened portion disposed in thecasting cavity, and the impeller may be cast directly upon the knurledor roughened portion of the shaft. The double carriage arrangementprovides adequate movement for introducing and freeing relatively longmembers upon which castings may be formed.

The matching mold inserts shownat I2 and I3 in Figure 9 havecomplementary casting cavities II and I5 for producing a metal object ofdifferent shape. One of these mold inserts I2 is carried by a moldholder on one of the master mold plates I2, 13, and the other moldinsert I3 is carried by the aligned mold holder on the other master moldplate. When the movable mold plate is closed into casting position, thecavities I4 and I5 make up together the complete cavity for casting thedesired object.

The mold inserts I2 and I3 are interchangeable with the mold insertsBil, and mold inserts with other forms of casting cavities may beprovided for casting objects of any desired shape or size. By using moldinserts with different casting cavities on the same mold plates at thesame time, different objects may be cast in the same casing operation.The mold inserts may be readily removed and replaced or interchanged,and it ispossible to change any one or more objects produced by themachine expeditiously and without changing the master mold plates.

The outer surfaoes of the heat insulating facin'gs 54 of the master moldplates l2 and I3 are provided with vertically disposed matching gates 18open at the top, as indicated at I9, and closed at the bottom at (Figure2). These gates open into or communicate with upwardly inclined runnersor gates 82 which, in turn, open into or communicate at their oppositeends with the casting cavities in the mold inserts. In Figure 2,communication between the gates or runners 82 and the casting cavities68 is aiforded through one of the spaces in which the blades of theimpeller are formed, the outer ends of the casting spaces for the otherblades of the impeller being closed by the surrounding refractory facing54.

Instead of having a portion of the casting cavity open to the refractoryfacing 54, the cavity may be confined or enclosed wholly within themetal body of the mold insert, and matching openings may be provided asshown at 84 (Figure 9) for delivering the molten metal into the castingcavities from the gates or runners 82. In any event, the adjustablemounting of the mold holders 42 not only affords the adjustment alreadydescribed, but provides for adjusting the molten metal receivingopenings of the mold inserts into proper registration with the gates orrunners 82.

Where the mold is cooled, water or other cooling medium is supplied intothe cavities 40 in the master mold plates I2 and I by a cooling mediumsupply line 00 having, for example, flexible connection at 00 with thecavity 40 in the master mold plate I 0 and flexible connection at 90with the cavity 00 in the master mold plate I2. The cavity 00 of eachplate I2 and I0 is provided in proximity to the top thereof with airvent openings 03. Upright overflow pipes 04 within the cavities 00 ofthe respective plates I2 and I0 discharge through overflow or dischargelines 05.

In making up the mold inserts, these inserts are preferably machinedfrom the centers of the cavities in the mold holders to flt the cavitiesof the mold holders. As already pointed out, the mold inserts are fittedinto the cavities of the mold holders for use and are readily replacedby other mold inserts, as desired. These inserts enable any desired moldto be removed from any multiple or single set plate without disturbingthe balance of the molds or the machine setting. Moreover, the lockingand adjusting of the molds or mold holders are accomplishedindependently and without disturbing the machine setting in any way. Theuse of mold inserts with mold holders enables absolute accuracy and lowmold cost. The features of adjusting and holding the molds and insertsand of adjusting the.movable master mold plate are important aspects ofthis invention.

Instead of employing mold inserts in combination with the mold holders02, the mold holders may have the casting cavities formed directlytherein, within the scope of the present invention. This would eliminatethe necessity of separate mold inserts, and in such case the moldholders 42 would be removed from any multiple or single set plate andreplaced with other mold holders having different casting cavities toform different objects.

The right hand end of the machine as viewed in Figure I is provided witha metal heating furnace 00. This furnace 00 has a suitable burner 99positioned below the container I00 for the molten metal- The burner 00,which may be an oil or gas burner or any other suitable burner, issupplied with fuel through a fuel supply line I02, and, for example, inthe case of a gas burner, air may be admitted at I00. The fuel supplyline I02 is provided with a control valve indicated at I00. The furnace00 is supported in elevated position upon the base section I0 byuprights I05.

With the illustrated construction, the molten metal container I00 ispositioned in close proximity to the mold means. The furnace 90 iscovered as indicated at I00, and a suitable refractory lining may beprovided as indicated at I00. The molten metal container I00 has a spoutindicated at IIO, which opens into a refractory lead or trough II2. Thislead or trough II2 slopes downwardly through the refractory lining I00and covering of the furnace, and its opposite end is positioned todischarge the molten metal into the open upper ends of the gates whenthe mold is closed. The molten metal container I00 may be supportedwithin the furnace in any suitable or preferred manner, as by means ofdiametrically opposite bosses or trunnions I II which engage in slotsIIS in the furnace.

For the purpose of delivering the molten metal to the mold. I provide adisplacement plunger IIO (Figure 1) which is adapted to be lowered intothe molten metal container I00 to displace the molten metal therefromand to be raised out '01 the container I00. The plunger 0 is pivoted atII! to a link IIO, which link is in turn pivoted at IIO to an operatinglever I20. The lever I20 is pivoted at I2I to an arm or bracket I22flxed. for example, to the furnace 00. The lever I20 is maintained inthe position shown, with the displacement plunger Il0 elevated by meansof a spring I20 coiled, .for example, about an arcuate guide I20 pivotedat I20 to the lever I20.

The particular lever arrangement shown provides one suitable means formanually operating the plunger 0. This means may vary widely within thescope of this invention, and, as already pointed out, the plunger may beoperated automatically and in timed relation to the closing of the mold.When the mold is closed and the plunger IIO depressed into the containerI00, the level of the liquid metalrises in the container until itreaches the level of the spout Ill. The liquid metal will then flow outof the container through the trough or lead H2 and into the matchinggates 10 of the mold. Upon entering the mold plate, it is distributeddirect to the one or more mold inserts or mold members through theopenings provided in the insulating facings of the master mold plates.-When the mold receives all the metal necessary entirely to flll all ofthe impressions or casting cavities, the metal will rise and stand inthe refractory lead, at which time the operator will make the necessarymotion mechanically to cause the plunger IIO to rise up out of thecontainer I00.

The speed at which the plunger is operated regulates the flow of metalfrom the container, and, as already pointed out, this displacementmethod in conjim'ction with the arrangement of the mold plates resultsin utilization of the force of gravity in filling the molds and permitsaccu rately controlling the amount of metal delivered to the mold platesin accordance with that required properly to fill the molds. Thedisplace ment method minimizes the time and heat loss of getting themetal from the container to the mold plate, and oxidation of the metalcaused by exposure to the atmosphere is rediiced.

By its position in the opening I at the top of the furnace 00, theplunger 0 is subjected to the hot gases or heat of the furnace, so thatit will not chill the molten metal in the container I00 when lowered,into the same. The plunger I I0 is preferably made of carborundum or ofa combination of insulating and refractory. material of the characteremployed, as the facings 50, cast into shape, or of other suitablematerial, so that the plunger will not. be disintegrated or otherwisedeleteriously affected by the hot metal, particularly by molten aluminumor any of its bronze alloys. 7

With the plunger displacement method of delivering the molten metal tothe mold means of the machine, the plunger does not require a close fitin the molten metal container I 00. If the plunger wears down, itsoperation may be adjusted at III to secure proper displacement of themolten metal from the container I00 when the plunger-is lowered into thesame. Moreover, with the utilization of the force of gravityindelivering the molten metal into the mold means, the danger offlashing of molten metal, particu larly if the molds do not closetightly, is eliminated. When the molten metal is delivered to the moldmeans under high pressures, as commonly done heretofore in the art, thisdanger of flashing of hot metal from the mold has presented a diiiicultproblem.

As the molten metal passes through the openings in the refractoryiacings 54 or the master mold plate, heat loss from the molten metal isreduced or substantially eliminated by reason of the heat insulatingcharacter of these faclngs. This prevents chilling or solidification orthe molten metal in the gate or runner means or elsewhere in its passageto the mold, and assures that the molten metal is delivered into themold in the desired molten condition completely to fill the mold andproduce good homogeneous and dense castings at all times. Moreover, themaintenance of the metal in molten condition in its passage through thegate and runner means eliminates cleaning of gates and runners irom thefinished work and clogging of the metal in its passage to the moldmeans. The arrangement of the master mold plates permits the moltenmetal to drain iromthe runners and gates in the heat insulating iacingslwhen the mold plates are parted by moving the mold plate l2 away fromthe mold plate l3, and this molten metalwhich drains from the runnersand gates in the insulating facings flows into the removable tray orcrucible ll.

Where a cooling medium isheld and circulated directly within'the mastermold plates I2 and I3, it will be noted that the mold holders 4!, whichare of good conducting material, are in direct contact therewith, andthis, together with the good conductivity of the mold inserts 60,extracts the heat from the molten metal in the casting cavities to. Thiscooling hastens the congeal in or solidification of the hot metal in thecasting cavities. At the same time, the insulating facings 54 preventany cooling action upon the molten metal passing through the openings inthese iacings 54, with the advantages already set forth.

The large cooling bodies provided in the master mold plates of mypresent invention provide for rapidly and effectively dissipating theheat from the mold holders and mold inserts. This protects these partsagainst cracking or other injury under excessive temperatures during theoperation of the machine.

It is to be understood that the metal will congeal or solidify in themold cavities with natural cooling, and that the'hollow formation andcooling medium may be omitted within the scope of the present invention.It is to be further understood that heat may be applied to the castingmolds to maintain the metal in the desired molten condition until thecasting cavities are completely filled. The top of the gate 18 in thefacing 54 of the mold plate I! may be provided with an upwardlyextending funnel-like portion I40, ii desired. The top of the furnace isshown as provided with a cover I42 having an opening 3 through which theplunger H6 operates. The facing plates 5t are preferably provided withnotches, as indicated at I45 inFigure 2, to permit the escapeof air orgas from the casting cavities so that there will not be any trapping ofsuch air or gas in these cavities such as might impair the homogeneityof the castings.

In the operation of the machine, the moldis closed by moving the movablemaster mold plate l2 into closed and accurate matching engagement withthe relatively stationary mold plate 13. The mold holders andmoldinserts, as well as the gates and runners in the respective master moldplates, match accurately, and when the mold is closed the plunger H6 isoperated to discharge the molten metal into the mold by displacement. Assoon as the mold cavities are filled and the metal in these cavities isset, the mold plate II is parted from the mold plate II, and theoverflow and waste metal in the openings in the face plates 54 drainsinto the crucible II. Where the operation of the machine is automatic,it is timed to permit removal of the cast objects while the mold plateI! is parted from the plate ll. The cycle of operation is repeated asoften as desired.

I do not intend to be limited to the precise details shown or described.

, I claim:

1. In combination, a master mold plate, a mold holder having screwthreaded connection with said plate, a mold removably mounted in saidmold holder, a heat insulating racing mounted on said mold plate andhaving an opening to receive said mold and gate means communicating withsaid opening for delivering molten metal to said mold, means forrotating said mold holder to adjust the position of said mold relativeto the surface of said heat insulating facing, and means connected withthe end of said mold holder opposite said mold {or locking said moldholder in adjusted position. v

2. In combination, a frame, a relatively sta-- tionary master mold plateon said frame, carriage means mounted for movement toward and away fromsaid relatively stationary master mold plate, a relatively movablemaster mold plate mounted on said carriage means for movement to closedposition relative to said first mold plate and adapted to be partedtherefrom, readily removable casting molds on said mold plates, and.heat insulating facings formed of a material of low heat-conductingcapacity mounted on said" mold plates and having cooperating gate meansformed in said heat insulating facings for delivering molten metal tosaid molds.

3. In combination, a frame, a relatively stationary master mold plate onsaid frame, carriage means mounted for movement toward and away fromsaid relatively stationary mold plate, a relatively movable master moldplate mounted on said carriage means for movement to closed positionrelative to said first mold plate and adapted to be parted therefrom,readily removable casting molds on said plates, heat insulating Iacingsformed of a material of low heat-conducting capacitymounted on said moldplates and having cooperating gate means formed in said heat in- 5sulating facings for delivering molten metal to saidmolds, and means foradjusting one of said mold plates to provide matching relation of saidplates and the casting molds and gate means thereon.

4. In combination, a frame, a relatively stationary master mold plate onsaid frame, a carriage mounted for movement on said frame toward andaway from said relatively stationary mold plate, a second carriagemounted for movement on said first carriage toward and away from saidrelatively stationary mold plate, a relatively movable master moldmounted on said second carriage for movement to closed position relativesaid first mold plate and adapted to be parted therefrom, casting moldson said mold plates, heat insulating facings formed of a material of lowheat-conducting capacity mounted on said mold plates and havingcooperating gate means for delivering molten metal to said molds, meansfor adjusting said casting molds in said plates and for securing same inadjusted position, and means for adjusting one of said mold plates toprovide matching relation of said plates and the casting' molds and gatemeans thereon.

5. In combination, a mold plate having a cavity therein, said platehaving aligned openings in the walls at opposite sides of said cavity, atubular mold holder fitting through said openings, a threaded memberheld to said plate and having threaded engagement with said mold holderto produce axial movement of said mold holder by turning thereof, a nuthaving threaded engagement with said mold holder and cooperating withsaid plate to lock said mold holder in adjusted position, and a moldinsert removably fitted in said holder.

6. In combination, a pair of relatively movable molds forming a moldcavity. cooling means therefor, complementary parts formed of heatinsulating material carried by said molds and forming gate meanscommunicating with said mold cavity, said parts being substantiallynon-conductive as regards the transmission or heat so that moltenmaterial in the gate means remains in molten condition after the metalin the cooled mold cavity becomes solid, means for parting said molds,and means for receiving the molten material flowing from said gate meanswhen the molds are parted, said receiving means retaining the moltenmaterial from the gate means in a pool in which only the surface isexposed.

7. In a molding machine, a hollow mold plate having opposite walls,there being aligned apertures in said wall and one of said walls havingan enlarged recess about the aperture therein, a tubular mold holderdisposed in said aligned apertures and having a flange at one enddisposed in said recess, means adjustably fixing the position of saidmold holder in said aligned apertures, and a mold insert removablydisposed in the tubular mold holder and having a head disposed againstsaid flange.

8. In a molding machine, a hollow mold plate having opposite wallsprovided with aligned apertures, one of said walls having an enlargedrecess about the aperture therein, a tubular mold holder extendingthrough said aligned apertures and having a head disposed in said recessand a threaded connection with said recessed mold plate wall, the flangeend of said tubular mold holder having an enlarged interior bore and theopposite end having a smaller tool receiving bore, a mold insert havinga shouldered head and a shank portion adapted to be disposed in saidenlarged bore with the shouldered head disposed against the flange ofsaid mold holder, a heat insulating facing secured to said one wall ofthe mold plate and having an aperture adapted to receive the head end ofsaid mold insert, rotation of said mold holder serving to position thehead of said mold insert substantially flush with the outer surface ofsaid heat insulating facing, and means at said other end of the moldholder for locking the latter in adjusted position in the mold plate.

DONALD H. GARTH.

